"We foresee great peril if governments and scientists don't take action now to render nuclear weapons obsolete and to prevent further climate change," he added.

The Bulletin of the Atomic Scientists has kept a Doomsday clock since 1947 as a reminder of the dangers of nuclear proliferation.

The publication, whose contributors have included Albert Einstein, was set up by scientists who had worked on the Manhattan Project, which developed the atomic bombs detonated over the Japanese cities of Hiroshima and Nagasaki in 1945.

At simultaneous events in London and Washington, the clock's big hand was pushed forward again, its sixth move since the end of the Cold War.

"We stand at the brink of a Second Nuclear Age. Not since the first atomic bombs were dropped on Hiroshima and Nagasaki has the world faced such perilous choices," said the bulletin in a statement.

"North Korea's recent test of a nuclear weapon, Iran's nuclear ambitions, a renewed US emphasis on the military utility of nuclear weapons, the failure to adequately secure nuclear materials, and the continued presence of some 26,000 nuclear weapons in the United States and Russia are symptomatic of a failure to solve the problems posed by the most destructive technology on Earth."

Each of the two nations' warheads was between eight and 40 times more powerful than the one dropped on Hiroshima and 50 of them could kill 200 million people, the statement said.

It also criticised the US, Russia and other signatories to the Nuclear Non-Proliferation Treaty for having "failed in their obligation to make serious strides toward disarmament".

The London event was held at the Royal Society, Britain's top scientific institution, whose president Martin Rees stressed the threat of climate change as well as nuclear proliferation.

"Nuclear weapons still pose the most catastrophic and immediate threat to humanity, but climate change and emerging technologies in the life sciences also have the potential to end civilization as we know it," he said.

The statement added that the expansion of civilian nuclear power programmes around the world "increases the risk of nuclear proliferation" because enrichment facilities can be modified to produce uranium for weapons use.

First set at seven minutes to midnight -- a phrase that has become part of pop culture -- the clock moved 17 times in response to global events. The most recent shift was in 2002 when it moved forward two minutes because the US withdrew from the Anti-Ballistic Missile Treaty and terrorists were known to be seeking nuclear and biological weapons.

earlier related report
Doomsday clock since 1947
London (AFP) Jan 17 - The movements of the symbolic Doomsday Clock, set up by the The Bulletin of the Atomic Scientists, a prominent group of international scientists, together with reasons cited.

- 1947: Seven minutes to midnight

The clock first appears as a symbol of nuclear danger.

- 1949: Three minutes to midnight

The Soviet Union explodes its first atomic bomb.

- 1953: Two minutes to midnight

The United States and the Soviet Union test thermonuclear devices within nine months of one another.

- 1960: Seven minutes to midnight

Growing public understanding that nuclear weapons made war between the major powers irrational amid greater international scientific cooperation and efforts to aid poor nations.

- 1963: Twelve minutes to midnight

The US and Soviet signing of the Partial Test Ban Treaty "provides the first tangible confirmation of what has been the Bulletin's conviction in recent years -- that a new cohesive force has entered the interplay of forces shaping the fate of mankind."

- 1968: Seven minutes to midnight

France and China acquire nuclear weapons; wars rage in the Middle East, the Indian subcontinent, and Vietnam; world military spending increases while development funds shrink.

- 1969: Ten minutes to midnight

The US Senate ratifies the Nuclear Non-Proliferation Treaty.

- 1972: Twelve minutes to midnight

The United States and the Soviet Union sign the first Strategic Arms Limitation Treaty and the Anti-Ballistic Missile Treaty.

- 1974: Nine minutes to midnight

SALT talks reach an impasse; India develops a nuclear weapon.

- 1980: Seven minutes to midnight

The deadlock in US-Soviet arms talks continues; nationalistic wars and terrorist actions increase; the gulf between rich and poor nations grows wider.

- 1981: Four minutes to midnight

Both superpowers develop more weapons for fighting a nuclear war. Terrorist actions, repression of human rights, and conflicts in Afghanistan, Poland and South Africa add to world tension.

- 1984: Three minutes to midnight

The arms race accelerates.

- 1988: Six minutes to midnight

The United States and the Soviet Union sign a treaty to eliminate intermediate-range nuclear forces; superpower relations improve; more nations actively oppose nuclear weapons.

- 1990: Ten minutes to midnight

The Cold War ends as the Iron Curtain falls.

- 1991: Seventeen minutes to midnight

The United States and the Soviet Union sign the long-stalled Strategic Arms Reduction Treaty (START) and announce further unilateral cuts in tactical and strategic nuclear weapons.

- 1995: Fourteen minutes to midnight

Further arms reductions stall while global military spending continues at Cold War levels. Risks of nuclear "leakage" from poorly guarded former Soviet facilities increase.

- 1998: Nine minutes to midnight

India and Pakistan "go public" with nuclear tests. The United States and Russia cannot agree on further deep reductions in their nuclear stockpiles.

- 2002: Seven minutes to midnight

The United States rejects a series of arms control treaties and announces it will withdraw from the Anti-Ballistic Missile Treaty. Terrorists seek to acquire and use nuclear and biological weapons.

- 2007: Five minutes to midnight.

North Korea's recent test of a nuclear weapon, Iran's nuclear ambitions, a renewed emphasis on the military utility of nuclear weapons," and the continued presence of 26,000 US and Russian nuclear weapons are cited.

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